Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Information amidst noise: preserved codes, error correction, and fault tolerance in a quantum world

Hui Khoon Ng

Published Jan 1, 2010• 0 citations
Publisher

Abstract

For my dad, whose secret ambition has always been to be a physicist, for my mum, for being the strong woman that she is, and of course, for my husband, for always being here. ivv Acknowledgments Looking back at the five years I have spent in Caltech as a part of the Institute of Quantum Information (IQI), I cannot help but consider myself incredibly fortunate to have had guidance from so many people. The first person I have to thank is of course my advisor John Preskill. He has put together the amazing place that is IQI, with its constant flux of visitors, postdocs and students, offering me an invaluable chance to meet so many talented people in the field. Along with sharing his insights in physics and always extending a willing hand in times of difficulty, he taught me a most valuable

DOI
10.7907/mr2r-fh44.

Related papers

Controlling atomic motion: From single particle classical mechanics to many body quantum dynamics

James L. Hanssen

Dedicated to my wife Laura and my parents. Without their help, none of this would have been possible. Acknowledgments First and foremost, I would like to thank my advisor, Mark Raizen. I was so fortunate that he took a chance on a kid with no experience with atomic physics experiments. He let me into the lab, showed me the exciting world of atomic physics, and taught me how to be an experimental physicist. He has always found the interesting topics to study and has creative ideas to tackle any problem that comes along. I am grateful for my time in the lab, and I look forward to the new results that will come from the experiments. Next I would like to thank my co-workers: Todd Meyrath, Florian Schreck and Chih-Sung Chuu. For the past several years we have worked side by side on a variety of projects most of which are described in the last chapter. Todd is a very talented man who I have had the pleasure to know since beginning graduate school. He is the one who got me interested in cold

•Jan 1, 2004•1 citation

The Complexity of Noise: A Philosophical Outlook on Quantum Error Correction

Amit Hagar

Synthesis lectures on quantum computing•Jan 1, 2010•2 citations

Protecting information in a quantum world: from cryptography to error correction

Anthony Leverrier

•Sep 27, 2017•0 citations

Symmetries of non-contextuality inequalities and the statistical robustness of experimental implementations

Gustavo Balvedi Pimentel

com apoio da Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Brasil.Processos nº 2022/01421-9 e nº 2022/14069-1.Eu agradeço muito pelo suporte financeiro, que me permitiu atender eventos importantes do meu campo de pesquisa e a fazer um intercâmbio inesquecível.iv I would first like to thank my advisor, Bárbara Amaral.Her guidance over these almost four years of undergraduate and master's studies has been essential to my development as a student and researcher.Thank you for all your patience, for giving me so many incredible opportunities, and for showing me that it is possible to do physics without giving up on other important aspects of life.Thank you for being an incredible person, in whom I draw inspiration.I hope to continue learning a lot from you and gossiping over coffee breaks at conferences and IFQIFs.To my parents, Maria de Fátima and Jones, who are my foundation and the loves of my life.I am immensely grateful for all the support you have given me.This work is largely the result of your efforts.Mom, thank you for being strong, loving and for teaching me to believe in myself.Dad, thank you for supporting me, making awful jokes (which I laugh at from time to time), and for teaching me that life is too short not to enjoy the people we love.So thank you very much, I love you.To my siblings, Gabriela and Matheus, for being my biggest inspirations, even though I try hard not to admit it in front of you.Gabi, thank you for being the sweetest person I know (and the fiercest too!).You have the gift of making me feel welcome and comfortable.Being with you is easy.Math, thanks for getting excited about me studying something remotely close to quantum computing and genuinely believing that I'm going to get rich from it.If that happens, although it's highly unlikely, I'll dedicate part of the fortune to you.But beyond that, thank you for showing me that someone so serious and responsible can be so playful and kind.And to my brother and sister-in-law, Luc and Malu, thank you for making Gabi and Math so happy.I love you all.And Malu, thanks for Sosô.To my grandparents, Eunice, Jurandir, Victória and Olize.Abuela, know that the most important part of who I am today comes from you.Thank you for teaching me to laugh on difficult days and to look at life through the eyes of a child.Grandpa, I didn't have the privilege of knowing you, but thank you for raising this family with grandma.Vivitória, you're not here anymore either, but I'll never forget talking to you by the wood-burning stove on cold mornings in Caçador.And Grandpa, "Life is bitter enough already, isn't it?Barbarity."So I'll try to write happier things next.

•Feb 28, 2025•0 citations

The Fragility and Resilience of Quantum Information

Christopher A. Fuchs

APS•Nov 1, 1999•0 citations

Spingineering : quantum control in the presence of relaxation

Benjamin Recht

For certain problems quantum resources can exponentially increase computing power, but these quantum resources are very fragile in practice. When a quantum system interacts with an external environment, it undergoes decoherence the loss of quantum correlation and relaxation the loss of energy and eventually all of the quantum information is lost. Here we show a general principle of using unitary operators to suppress relaxation processes. Unitary operations do not cool a quantum system and seem an unlikely candidate for preventing irreversible thermodynamic heating processes, but surprisingly most decoherence processes can be corrected or ameliorated using open loop control with unitary controllers. We examine the different mechanisms of decoherence and relaxation on simple spin systems and discuss when the modes can be corrected. We show experimentally the feasibility of our correction schemes using nuclear magnetic resonance. We also demonstrate control of the nuclear spins over long time scales. Finally, we discuss the applications of unitary correction to higher dimensional systems and the potential applications to quantum information processing. Thesis Supervisor: Neil Gershenfeld Title: Associate Professor Spingineering: Quantum Control in the Presence of Relaxation by Benjamin Harris Recht Submitted to the Media Arts and Sciences department in partial fulfillment of the requirements for the degree of Master of Science in Media Arts and Sciences at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY June 2002 Thesis Advisor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Neil Gershenfeld Associate Professor Department of Media Arts and Sciences Massachusetts Institute of Technology Thesis Reader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Isaac Chuang Associate Professor Department of Media Arts and Sciences Massachusetts Institute of Technology Thesis Reader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seth Lloyd Professor Department of Mechanical Engineering Massachusetts Institute of Technology Acknowledgments This thesis, being no different than any other, would have not been possible without some truly remarkable people. I would like to thank my advisor Neil Gershenfeld for his support and guidance through my first two years and my readers: Isaac Chuang for introducing me to and guiding me through the quantum world, and Seth Lloyd for always saying just the right thing at the right time. I owe a large thank you to Yael Maguire for inspiring this work and his eagerness to discuss my progress. Thanks to Matthias Steffen and Yael for making sure that my theorist hands never broke the ever fussy 500 MHz NMR spectrometer. I would also like to thank Aram Harrow and Ali Rahimi for invaluable discussions and suggestions. Thanks to Jason Taylor for bearing with me in the confines of our office and to the rest of the PHM crew: Matt, Rehmi, Ben, Rich, Ravi, Bernd, John-Paul, Dan, Caroline, Esa, Femi. Thanks to Linda Peterson and Pat Sokaloff for taking extra time to care about all of us lost and helpless graduate students. I also owe a great deal of thanks to Susan MurphyBottari, Mike Houlilhan, and Liz Hennessey for making the PHM machine run as smoothly as it does. I send much love and respect to the unlockedgroove crew and all of the people who frequent to the Appliance of Science for helping me maintain my sanity. Thank you Mom and Dad for 24 years of constant support and Marissa for never forgetting to tell me when I’m wrong. Thank you Lauren for being exactly who you are. Thanks to the MIT Media Laboratory and the Things That Think Consortium. This thesis would not have been possible without the constant support of Nicotine, Caffeine, Alcohol, and Cholesterol. Thank you for better living through chemistry.

•Jan 1, 2002•1 citation
For my dad, whose secret ambition has always been to be a physicist, for my mum, for being the strong woman that she is, and of course, for my husband, for always being here. ivv Acknowledgments Looking back at the five years I have spent in Caltech as a part of the Institute of Quantum Information (IQI), I cannot help but consider myself incredibly fortunate to have had guidance from so many people. The first person I have to thank is of course my advisor John Preskill. He has put together the amazing place that is IQI, with its constant flux of visitors, postdocs and students, offering me an invaluable chance to meet so many talented people in the field. Along with sharing his insights in physics and always extending a willing hand in times of difficulty, he taught me a most valuable
Dedicated to my wife Laura and my parents. Without their help, none of this would have been possible. Acknowledgments First and foremost, I would like to thank my advisor, Mark Raizen. I was so fortunate that he took a chance on a kid with no experience with atomic physics experiments. He let me into the lab, showed me the exciting world of atomic physics, and taught me how to be an experimental physicist. He has always found the interesting topics to study and has creative ideas to tackle any problem that comes along. I am grateful for my time in the lab, and I look forward to the new results that will come from the experiments. Next I would like to thank my co-workers: Todd Meyrath, Florian Schreck and Chih-Sung Chuu. For the past several years we have worked side by side on a variety of projects most of which are described in the last chapter. Todd is a very talented man who I have had the pleasure to know since beginning graduate school. He is the one who got me interested in cold
com apoio da Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Brasil.Processos nº 2022/01421-9 e nº 2022/14069-1.Eu agradeço muito pelo suporte financeiro, que me permitiu atender eventos importantes do meu campo de pesquisa e a fazer um intercâmbio inesquecível.iv I would first like to thank my advisor, Bárbara Amaral.Her guidance over these almost four years of undergraduate and master's studies has been essential to my development as a student and researcher.Thank you for all your patience, for giving me so many incredible opportunities, and for showing me that it is possible to do physics without giving up on other important aspects of life.Thank you for being an incredible person, in whom I draw inspiration.I hope to continue learning a lot from you and gossiping over coffee breaks at conferences and IFQIFs.To my parents, Maria de Fátima and Jones, who are my foundation and the loves of my life.I am immensely grateful for all the support you have given me.This work is largely the result of your efforts.Mom, thank you for being strong, loving and for teaching me to believe in myself.Dad, thank you for supporting me, making awful jokes (which I laugh at from time to time), and for teaching me that life is too short not to enjoy the people we love.So thank you very much, I love you.To my siblings, Gabriela and Matheus, for being my biggest inspirations, even though I try hard not to admit it in front of you.Gabi, thank you for being the sweetest person I know (and the fiercest too!).You have the gift of making me feel welcome and comfortable.Being with you is easy.Math, thanks for getting excited about me studying something remotely close to quantum computing and genuinely believing that I'm going to get rich from it.If that happens, although it's highly unlikely, I'll dedicate part of the fortune to you.But beyond that, thank you for showing me that someone so serious and responsible can be so playful and kind.And to my brother and sister-in-law, Luc and Malu, thank you for making Gabi and Math so happy.I love you all.And Malu, thanks for Sosô.To my grandparents, Eunice, Jurandir, Victória and Olize.Abuela, know that the most important part of who I am today comes from you.Thank you for teaching me to laugh on difficult days and to look at life through the eyes of a child.Grandpa, I didn't have the privilege of knowing you, but thank you for raising this family with grandma.Vivitória, you're not here anymore either, but I'll never forget talking to you by the wood-burning stove on cold mornings in Caçador.And Grandpa, "Life is bitter enough already, isn't it?Barbarity."So I'll try to write happier things next.
For certain problems quantum resources can exponentially increase computing power, but these quantum resources are very fragile in practice. When a quantum system interacts with an external environment, it undergoes decoherence the loss of quantum correlation and relaxation the loss of energy and eventually all of the quantum information is lost. Here we show a general principle of using unitary operators to suppress relaxation processes. Unitary operations do not cool a quantum system and seem an unlikely candidate for preventing irreversible thermodynamic heating processes, but surprisingly most decoherence processes can be corrected or ameliorated using open loop control with unitary controllers. We examine the different mechanisms of decoherence and relaxation on simple spin systems and discuss when the modes can be corrected. We show experimentally the feasibility of our correction schemes using nuclear magnetic resonance. We also demonstrate control of the nuclear spins over long time scales. Finally, we discuss the applications of unitary correction to higher dimensional systems and the potential applications to quantum information processing. Thesis Supervisor: Neil Gershenfeld Title: Associate Professor Spingineering: Quantum Control in the Presence of Relaxation by Benjamin Harris Recht Submitted to the Media Arts and Sciences department in partial fulfillment of the requirements for the degree of Master of Science in Media Arts and Sciences at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY June 2002 Thesis Advisor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Neil Gershenfeld Associate Professor Department of Media Arts and Sciences Massachusetts Institute of Technology Thesis Reader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Isaac Chuang Associate Professor Department of Media Arts and Sciences Massachusetts Institute of Technology Thesis Reader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seth Lloyd Professor Department of Mechanical Engineering Massachusetts Institute of Technology Acknowledgments This thesis, being no different than any other, would have not been possible without some truly remarkable people. I would like to thank my advisor Neil Gershenfeld for his support and guidance through my first two years and my readers: Isaac Chuang for introducing me to and guiding me through the quantum world, and Seth Lloyd for always saying just the right thing at the right time. I owe a large thank you to Yael Maguire for inspiring this work and his eagerness to discuss my progress. Thanks to Matthias Steffen and Yael for making sure that my theorist hands never broke the ever fussy 500 MHz NMR spectrometer. I would also like to thank Aram Harrow and Ali Rahimi for invaluable discussions and suggestions. Thanks to Jason Taylor for bearing with me in the confines of our office and to the rest of the PHM crew: Matt, Rehmi, Ben, Rich, Ravi, Bernd, John-Paul, Dan, Caroline, Esa, Femi. Thanks to Linda Peterson and Pat Sokaloff for taking extra time to care about all of us lost and helpless graduate students. I also owe a great deal of thanks to Susan MurphyBottari, Mike Houlilhan, and Liz Hennessey for making the PHM machine run as smoothly as it does. I send much love and respect to the unlockedgroove crew and all of the people who frequent to the Appliance of Science for helping me maintain my sanity. Thank you Mom and Dad for 24 years of constant support and Marissa for never forgetting to tell me when I’m wrong. Thank you Lauren for being exactly who you are. Thanks to the MIT Media Laboratory and the Things That Think Consortium. This thesis would not have been possible without the constant support of Nicotine, Caffeine, Alcohol, and Cholesterol. Thank you for better living through chemistry.